lustre: simplify the living hell out of ksocknal_lib_recv_kiov()

... by using ITER_BVEC recvmsg

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/lustre/lnet/klnds/socklnd/socklnd.h b/drivers/staging/lustre/lnet/klnds/socklnd/socklnd.h
index a56632b..d5efb42 100644 (file)
--- a/drivers/staging/lustre/lnet/klnds/socklnd/socklnd.h
+++ b/drivers/staging/lustre/lnet/klnds/socklnd/socklnd.h
@@ -86,8 +86,10 @@ struct ksock_sched {                         /* per scheduler state */
        int                     kss_nconns;     /* # connections assigned to
                                                 * this scheduler */
        struct ksock_sched_info *kss_info;      /* owner of it */
-       struct page             *kss_rx_scratch_pgs[LNET_MAX_IOV];
-       struct kvec             kss_scratch_iov[LNET_MAX_IOV];
+       union {
+               struct bio_vec          kss_scratch_bvec[LNET_MAX_IOV];
+               struct kvec             kss_scratch_iov[LNET_MAX_IOV];
+       };
 };
 
 struct ksock_sched_info {

diff --git a/drivers/staging/lustre/lnet/klnds/socklnd/socklnd_lib.c b/drivers/staging/lustre/lnet/klnds/socklnd/socklnd_lib.c
index 6a17757..8479b53 100644 (file)
--- a/drivers/staging/lustre/lnet/klnds/socklnd/socklnd_lib.c
+++ b/drivers/staging/lustre/lnet/klnds/socklnd/socklnd_lib.c
@@ -259,67 +259,11 @@ ksocknal_lib_recv_iov(struct ksock_conn *conn)
        return rc;
 }
 
-static void
-ksocknal_lib_kiov_vunmap(void *addr)
-{
-       if (!addr)
-               return;
-
-       vunmap(addr);
-}
-
-static void *
-ksocknal_lib_kiov_vmap(lnet_kiov_t *kiov, int niov,
-                      struct kvec *iov, struct page **pages)
-{
-       void *addr;
-       int nob;
-       int i;
-
-       if (!*ksocknal_tunables.ksnd_zc_recv || !pages)
-               return NULL;
-
-       LASSERT(niov <= LNET_MAX_IOV);
-
-       if (niov < 2 ||
-           niov < *ksocknal_tunables.ksnd_zc_recv_min_nfrags)
-               return NULL;
-
-       for (nob = i = 0; i < niov; i++) {
-               if ((kiov[i].kiov_offset && i > 0) ||
-                   (kiov[i].kiov_offset + kiov[i].kiov_len != PAGE_SIZE && i < niov - 1))
-                       return NULL;
-
-               pages[i] = kiov[i].kiov_page;
-               nob += kiov[i].kiov_len;
-       }
-
-       addr = vmap(pages, niov, VM_MAP, PAGE_KERNEL);
-       if (!addr)
-               return NULL;
-
-       iov->iov_base = addr + kiov[0].kiov_offset;
-       iov->iov_len = nob;
-
-       return addr;
-}
-
 int
 ksocknal_lib_recv_kiov(struct ksock_conn *conn)
 {
-#if SOCKNAL_SINGLE_FRAG_RX || !SOCKNAL_RISK_KMAP_DEADLOCK
-       struct kvec scratch;
-       struct kvec *scratchiov = &scratch;
-       struct page **pages = NULL;
-       unsigned int niov = 1;
-#else
-#ifdef CONFIG_HIGHMEM
-#warning "XXX risk of kmap deadlock on multiple frags..."
-#endif
-       struct kvec *scratchiov = conn->ksnc_scheduler->kss_scratch_iov;
-       struct page **pages = conn->ksnc_scheduler->kss_rx_scratch_pgs;
+       struct bio_vec *bv = conn->ksnc_scheduler->kss_scratch_bvec;
        unsigned int niov = conn->ksnc_rx_nkiov;
-#endif
        lnet_kiov_t   *kiov = conn->ksnc_rx_kiov;
        struct msghdr msg = {
                .msg_flags = 0
@@ -328,44 +272,26 @@ ksocknal_lib_recv_kiov(struct ksock_conn *conn)
        int i;
        int rc;
        void *base;
-       void *addr;
        int sum;
        int fragnob;
        int n;
 
-       /*
-        * NB we can't trust socket ops to either consume our iovs
-        * or leave them alone.
-        */
-       addr = ksocknal_lib_kiov_vmap(kiov, niov, scratchiov, pages);
-       if (addr) {
-               nob = scratchiov[0].iov_len;
-               n = 1;
-
-       } else {
-               for (nob = i = 0; i < niov; i++) {
-                       nob += scratchiov[i].iov_len = kiov[i].kiov_len;
-                       scratchiov[i].iov_base = kmap(kiov[i].kiov_page) +
-                                                kiov[i].kiov_offset;
-               }
-               n = niov;
+       for (nob = i = 0; i < niov; i++) {
+               nob += bv[i].bv_len = kiov[i].kiov_len;
+               bv[i].bv_page = kiov[i].kiov_page;
+               bv[i].bv_offset = kiov[i].kiov_offset;
        }
+       n = niov;
 
        LASSERT(nob <= conn->ksnc_rx_nob_wanted);
 
-       rc = kernel_recvmsg(conn->ksnc_sock, &msg, (struct kvec *)scratchiov,
-                           n, nob, MSG_DONTWAIT);
+       iov_iter_bvec(&msg.msg_iter, READ | ITER_BVEC, bv, n, nob);
+       rc = sock_recvmsg(conn->ksnc_sock, &msg, MSG_DONTWAIT);
 
        if (conn->ksnc_msg.ksm_csum) {
                for (i = 0, sum = rc; sum > 0; i++, sum -= fragnob) {
                        LASSERT(i < niov);
 
-                       /*
-                        * Dang! have to kmap again because I have nowhere to
-                        * stash the mapped address.  But by doing it while the
-                        * page is still mapped, the kernel just bumps the map
-                        * count and returns me the address it stashed.
-                        */
                        base = kmap(kiov[i].kiov_page) + kiov[i].kiov_offset;
                        fragnob = kiov[i].kiov_len;
                        if (fragnob > sum)
@@ -377,14 +303,6 @@ ksocknal_lib_recv_kiov(struct ksock_conn *conn)
                        kunmap(kiov[i].kiov_page);
                }
        }
-
-       if (addr) {
-               ksocknal_lib_kiov_vunmap(addr);
-       } else {
-               for (i = 0; i < niov; i++)
-                       kunmap(kiov[i].kiov_page);
-       }
-
        return rc;
 }